<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Button循环点击</title>
    <style>
        .pink {
            color: blue;
        }
    </style>
</head>

<body>
    <button class="pink">按钮1</button>
    <button>按钮2</button>
    <button>按钮3</button>
    <button>按钮4</button>

    <script>
        let btns = document.querySelectorAll("button");
        for (let i = 0; i < btns.length; i++) {
            btns[i].addEventListener("click", function () {
                document.querySelector(".pink").className = "";
                this.className = "pink";
            })
        };
    </script>
</body>

</html>